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The aim of this study is to validate the prognostic and predictive value of the non-synonymous cytidine deaminase (CDA) Lys(27)Gln polymorphism for hematological toxicity and survival using a randomized phase III adjuvant trial (Radiation Therapy Oncology Group (RTOG) 9704) in pancreatic cancer in which one treatment arm received gemcitabine. CDA is involved in gemcitabine inactivation, and there is conflicting data on the role of the non-synonymous CDA Lys(27)Gln polymorphism in predicting toxicity and survival in cancer patients treated with gemcitabine. RTOG 9704 randomized 538 patients after pancreatic resection to receive radiotherapy with either 5-fluorouracil (5-FU) or gemcitabine. CDA Lys(27)Gln polymorphism genotype was analyzed. We tested an association between CDA single-nucleotide polymorphism genotype and the survival outcome by the Cox proportional hazard model adjusting for other covariates, as well as toxicity by the logistic regression model. There is statistically significant more severe hematological toxicity in patients treated with gemcitabine with either the homozygote wild-type genotype (Lys/Lys) alone (odds ratio (OR)=0.06, P=0.01), or in combination with the heterozygote (Lys/Gln; OR=0.14, P=0.03) when compared with homozygote variant genotype (Gln/Gln) when adjusted for other covariates. This was not seen in the non-gemcitabine treated arm. There are no genotype differences with respect to survival outcome. In conclusion, in this prospective randomized adjuvant study of patients with pancreatic cancer, the CDA Lys(27)Gln polymorphism is validated as a predictive marker of gemcitabine hematological toxicity, but not with treatment response or survival.

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The human equilibrative nucleoside transporter (hENT1) protein transports gemcitabine into cells. Small retrospective studies in pancreatic cancer suggest that levels of hENT1 protein or messenger RNA may have prognostic value. We studied the predictive value of hENT1 levels in a cohort of pancreatic adenocarcinoma patients from the large prospective randomized adjuvant treatment trial RTOG9704.
In RTOG9704, 538 patients were assigned randomly, after surgical resection, to groups that were given either gemcitabine or 5-fluorouracil (5-FU). Immunohistochemistry for hENT1 was performed on a tissue microarray of 229 resected pancreatic tumors from RTOG9704 and scored as having no staining, low staining, or high staining. Associations between hENT1 protein and treatment outcome were analyzed by unconditional logistic regression analysis using the chi-square test and the Cox proportional hazards model.
HENT1 expression was associated with overall and disease-free survival in a univariate (hazard ratio [HR], 0.51; 95% confidence interval [CI], 0.29-0.91; P= .02; and HR, 0.57; 95% CI, 0.32-1.00; P= .05) and multivariate model in the group given gemcitabine (HR, 0.40; 95% CI, 0.22-0.75; P= .004; and HR, 0.39; 95% CI, 0.21-0.73; P= .003). hENT1 expression was not associated with survival in the group given 5-FU.
In this prospective randomized trial, hENT1 protein expression was associated with increased overall survival and disease-free survival in pancreatic cancer patients who received gemcitabine, but not in those who received 5-FU. These findings are supported by preclinical data; the gemcitabine transporter hENT1 is therefore a molecular and mechanistically relevant predictive marker of benefit from gemcitabine in patients with resected pancreatic cancer.

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The primary objective was to prospectively investigate the efficacy and toxicity of bolus 5-fluorouracil (5-FU) chemotherapy compared with the infusional 5-FU in combination with preoperative radiation in patients with locally advanced rectal cancer. Furthermore, in light of previous reports, toxicity profiles between men and women were also compared. Eighty-four consecutive patients with rectal adenocarcinoma were prospectively treated. There were no differences in tumour response, local recurrence or survival between bolus versus infusional groups or gender groups. In locally advanced rectal cancer, preoperative infusional chemotherapy combined with radiation was found to be less toxic than bolus chemotherapy and radiotherapy. Both regimens produced more toxic effects in women compared with men.

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Loss of TP53 function through gene mutation is a critical event in the development and progression of many tumour types including colorectal cancer (CRC). In vitro studies have found considerable heterogeneity amongst different TP53 mutants in terms of their transactivating abilities. The aim of this work was to evaluate whether TP53 mutations classified as functionally inactive (< or=20% of wildtype transactivation ability) had different prognostic and predictive values in CRC compared with mutations that retained significant activity.
TP53 mutations within a large, international database of CRC (n = 3583) were classified according to functional status for transactivation.
Inactive TP53 mutations were found in 29% of all CRCs and were more frequent in rectal (32%) than proximal colon (22%) tumours (P < 0.001). Higher frequencies of inactive TP53 mutations were also seen in advanced stage tumours (P = 0.0003) and in tumours with the poor prognostic features of vascular (P = 0.006) and lymphatic invasion (P = 0.002). Inactive TP53 mutations were associated with significantly worse outcome only in patients with Dukes' stage D tumours (RR = 1.71, 95%CI 1.25-2.33, P < 0.001). Patients with Dukes' C stage tumours appeared to gain a survival benefit from 5-fluorouracil-based chemotherapy regardless of TP53 functional status for transactivation ability.
Mutations that inactivate the transactivational ability of TP53 are more frequent in advanced CRC and are associated with worse prognosis in this stage of disease.

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Many radiosensitizers are in current clinical use. In addition, a myriad of potential new targeted therapies, which may also interact with radiation, are in clinical development. The clinical utility of new targeted therapies, in combination with existing radiation sensitizers (chemotherapies) requires further evaluation, as does the understanding of their acute and late radiation effects. Free radical scavengers appear to show promise as radioprotectors, but data for mucoprotection are less convincing.

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The role of early detection in cancer has shown improved survival for certain cancers, including colon cancer, cervical cancer and breast cancer. The possibility for early detection of pancreatic cancer may be realized by an improved understanding of the histology and molecular genetics of precursor lesions and cancerous lesions in pancreatic cancer and the development of sensitive and specific screening tests (both invasive and non-invasive) to detect early pancreatic cancer. The NIH-NCI Early Detection Research Network (EDRN) in Pancreatic Cancer has been focussed on the development and validation of new biomarkers for the detection of early pancreatic cancer. This review will focus on our understanding of the histologic and molecular model of pancreatic carcinogenesis, current strategies and limitations of screening for pancreatic cancer and the development and validation of new biomarkers for the early detection of pancreatic cancer.

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Purpose/Objective: Objective: The principal purpose of this trial was to prospectively investigate the differences in toxicity between pre-operative bolus and infusional 5-fluorouracil chemo-radiation schedules in the setting of locally advanced rectal cancer. Secondary endpoints included investigating the differences in toxicity between genders, and differences in outcomes between the two chemo-radiation schedules. Materials/Methods: Materials & Methods: Eighty-four consecutive patients with locally advanced rectal adenocarcinoma were treated with pre-operative bolus or infusional 5-fluorouracil and standard four-field pelvic irradiation. The subsequent surgery involved meso-rectal excision by anterior or abdomino-perineal resection with temporary ileostomy. Clinical and biochemical toxicity parameters were collected prospectively. Patient results were analysed 5 years following trial commencement. Results: Results: All eighty-four patients were assessed. There were 64 males and 20 females, with a median age of 60 years. The mean follow-up was 47 weeks. 50 patients received bolus 5-fluorouracil and 34 received infusional 5-fluorouracil. The group receiving bolus chemotherapy was found to have significantly higher rates of treatment induced biochemical and clinical side effects of any grade compared to those receiving infusional chemotherapy. These included anaemia, leucopaenia, thrombocytopaenia, stomatitis, and skin toxicity. Female patients were found to have significantly higher rates of side effects compared to male patients. These included anaemia, diarrhea, and skin toxicity. There was no significant difference in tumour-response, in terms of tumour down staging and local recurrence, or survival between the groups receiving bolus and infusional chemotherapy. Conclusions: Conclusion: Pre-operative infusional chemotherapy combined with radiation is less toxic than bolus chemotherapy in the setting of locally advanced rectal cancer. These regimens produced more side effects in female compared to male patients. No difference in tumour response was found between the different chemotherapy schedules. These findings warrant further investigation of the underlying mechanisms that may be responsible for the observed differences. It is hypothesised that there are molecular differences between male and female rectal cancer as we have previously demonstrated in colon cancer.

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We investigated the efficacy of hyperbaric oxygen therapy (HBOT) in the management of patients with radiation-induced late side effects, the majority of whom had failed previous interventions.
Of 105 eligible subjects, 30 had either died or were not contactable, leaving 75 who qualified for inclusion in this retrospective study. Patients answered a questionnaire documenting symptom severity before and after treatment (using Radiation Therapy Oncology Group criteria), duration of improvement, relapse incidence, and HBOT-related complications.
The rate of participation was 60% (45/75). Improvement of principal presenting symptoms after HBOT was noted in 75% of head-and-neck, 100% of pelvic, and 57% of "other" subjects (median duration of response of 62, 72, and 68 weeks, respectively). Bone and bladder symptoms were most likely to benefit from HBOT (response rate, 81% and 83%, respectively). Fifty percent of subjects with soft tissue necrosis/mucous membrane side effects improved with HBOT. The low response rate of salivary (11%), neurologic (17%), laryngeal (17%), and upper gastrointestinal symptoms (22%) indicates that these were more resistant to HBOT. Relapse incidence was low (22%), and minor HBOT-related complications occurred in 31% of patients.
Hyperbaric oxygen therapy is a safe and effective treatment modality offering durable relief in the management of radiation-induced osteoradionecrosis either alone or as an adjunctive treatment. Radiation soft tissue necrosis, cystitis, and proctitis also seemed to benefit from HBOT, but the present study did not have sufficient numbers to reliably predict long-term response.

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The CpG island methylator phenotype (CIMP) is observed in approximately 30% of colorectal cancer (CRC) cases and is characterized by the concurrent methylation of multiple CpG islands in tumor DNA. This phenotype (CIMP+) is more frequently observed in tumors with proximal location, microsatellite instability, and normal p53. Because it has previously been observed that each of these features is associated with a good survival benefit from 5-fluorouracil (5-FU)-based adjuvant chemotherapy, we investigated in the present study whether CIMP+ has independent predictive value. Experimental Design: CIMP+ status was evaluated in 103 stage III CRCs from patients treated with surgery alone and for an additional 103 cases from patients treated with surgery and adjuvant 5-FU-based chemotherapy. The two cohorts were randomly pair-matched for age, sex, and tumor site, and the median length of follow-up time was 39 months.
CIMP+ status predicted survival benefit from 5-FU treatment independently of microsatellite instability and p53 mutation status (relative risk = 0.22; 95% confidence interval, 0.06-0.84; P = 0.027). Unmeasured, high-risk confounding factors could only account for this association if they were unequally distributed between the two patient cohorts by a factor of at least 2-fold.
CIMP+ has independent predictive significance for the survival benefit from 5-FU chemotherapy in CRC. This molecular marker should be incorporated into prospective clinical trials of fluorouracil-based therapies to confirm its clinical value.

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A subgroup of colorectal cancers (CRC) referred to as the CpG island methylator phenotype (CIMP+) shows simultaneous methylation of multiple CpG islands. The clinicopathological and molecular characteristics of this phenotype remain uncertain however.
We analysed methylation of CpG islands in the p16 and MDR1 genes and MINT-2 clone in 275 stage II/III CRCs.
Concurrent methylation of two or more CpG islands was observed in 32% of cases and was considered to represent CIMP+. These were often poorly differentiated, had less TP53 mutations, and originated frequently in the proximal or higher stage CRC compared with CIMP- tumours (p<0.05 for each). CIMP+ had no prognostic significance in stage II or stage III CRC treated by surgery alone. hMLH1 methylated tumours comprised the majority (81%) of cases with microsatellite instability, were frequently observed in older female patients, were often poorly differentiated or CIMP+, and contained wild-type K-ras (p<0.05 for each). Females who were heterozygous or homozygous for the C677T MTHFR polymorphism were at increased risk of developing CIMP+ CRC (odds ratio 2.17, 95% confidence interval 1.03-4.57; p=0.037).
These observations made in a relatively large unselected series of CRC support the notion that CIMP+ characterises a subgroup of tumours with distinctive phenotypic features.